No bigger than a thumb, the human-shaped Robo-Q can kick a football, find its way out of a maze and dodge unexpected obstacles.
Measuring only 3.4 cm high, it is fitted with artificial intelligence enabling it to navigate and play games.
Built-in infrared sensors also allow the Robo-Q to walk around objects placed in its path.
Its ability to kick and pass a ball - with the use of a remote control - means the toy could be used to play miniature table football.
The two-legged micro robot, which is available in four different colours, will be sold in Japan from next February for Y3,500 (£21) before being released in Europe at a later date, according to Tomy Co, the Japanese toy manufacturer behind its production.
The tiny creation was among more than 100 different types of robots being showcased by companies, academics and organisations during Robo Japan 2008, a three-day convention of all things robotic, held in Yokohama.
Other exhibits at the event ranged from a robot suit, which helps the elderly carry heavy items, to a talking household robot with an "independent personality" called Wakamaru.
The previous title-holder for the world's smallest humanoid robot is a creation called "i-Sobot", also produced by Tomy Co, which measured 16.5cm high and went on sale in the UK last year.
Japan is an industry-leader in cutting-edge robotic creations, with the market for lifestyle-related robots expected to reach 7.2 trillion yen (£42 billion) by 2025, according to the Japan Robot Association.
http://www.telegraph.co.uk/news/worldnews/asia/japan/3187299/Worlds-smallest-walking-robot-unveiled-in-Japan.html